JP2008047567A - Solenoid-actuator, and differential apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve reliability in operation by reliable operation by suppressing the drop of attraction force during the stroke of the attraction movement of a movable core. <P>SOLUTION: A solenoid-actuator 1 comprises: a sidewall 65 that is a fixed core having an attractor 68 wound by a coil 55; and a plunger 49 that is a movable core capable of attracting and moving axially by the attractor 68 while being arranged coaxially to the attractor 68 of the sidewall 65. In this case, a recess 89 for reducing the radial thickness of the attractor 68 is formed at the radial outer-periphery side of the attractor 68, thus suppressing the flow of magnetic force in the radial direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a solenoid actuator used for a differential apparatus such as an automobile, and a differential apparatus using the solenoid actuator.

  As a conventional solenoid actuator, there is one described in Patent Document 1, for example.

  This solenoid actuator is applied to an automobile differential device. The differential differential can be locked and unlocked by a solenoid actuator.

  The solenoid actuator includes a fixed iron core around which a coil is wound and a movable iron core that can be sucked in the axial direction by a suction portion of the fixed iron core. The differential device can be locked up by interlocking the lock up member by suction movement of the movable iron core.

  The attraction movement for locking up and moving the movable iron core can be performed by forming a magnetic flux loop between the fixed iron core and the movable iron core by controlling energization of the coil. The return movement for unlocking the movable core is performed by the resilient force of the coil spring.

  In order to perform the unlocking quickly and reliably with such a differential device, the spring force of the coil spring is set strongly.

  However, if the spring force of the coil spring is simply set, it will affect the suction movement of the movable iron core, which may make it difficult to lock up.

That is, in the conventional structure, the relationship between the stroke of the moving movement of the movable core and the change in the suction force of the fixed core does not necessarily correspond to the change in the stroke of the spring force of the coil spring. There is a problem that the operation force may be deteriorated due to a decrease in the suction force during the suction movement stroke, resulting in a lack of reliability.
See JP-A-2005-288661

  The problem to be solved is that the suction force drops during the suction movement stroke of the movable iron core, which may cause a malfunction, and is unreliable.

  In order to improve the reliability of the operation, the present invention is arranged so that a coil is wound around a fixed iron core having a suction part, and is coaxially arranged with respect to the suction part of the fixed iron core and can be moved in the axial direction by the suction part. A solenoid actuator provided with a movable iron core is characterized in that a depression for reducing the radial thickness of the suction portion is formed on the radially outer peripheral side of the suction portion.

  The present invention relates to a solenoid actuator comprising a fixed iron core around which a coil is wound and having a suction part, and a movable iron core that is arranged coaxially with the suction part of the fixed iron core and can be moved in the axial direction by the suction part. In this embodiment, since the hollow portion for reducing the radial thickness of the suction portion is formed on the radially outer peripheral side of the suction portion, it is possible to suppress the magnetic force from flowing in the radial direction. Therefore, it is possible to suppress the suction force from dropping during the suction movement stroke of the movable iron core, and to improve the reliability by a reliable operation.

  The purpose of improving operation reliability was realized by the depression of the suction part.

[4-wheel drive vehicle]
FIG. 1 is a skeleton plan view of a four-wheel drive vehicle showing an arrangement of a differential device to which a solenoid actuator according to the present invention is applied.

  FIG. 1 shows a four-wheel drive vehicle as an example, and a solenoid actuator 1 according to a first embodiment of the present invention is applied to a front differential 3 as a differential device. The front differential 3 can be locked up by the operation of the solenoid actuator 1.

  The front differential 3 is rotatably supported by the differential carrier 4 via a bearing. Left and right front wheels 9 and 11 are linked to the front differential 3 via left and right axle shafts 5 and 7. A bevel gear 15 is engaged with the ring gear 13 of the front differential 3. Torque is input to the bevel gear 15 from the engine 17 via the transmission 19, the transfer 21, and the propeller shaft 23.

  On the other hand, torque is transmitted from the transfer 21 to the rear differential 27 via the propeller shaft 25. Left and right rear wheels 33 and 35 are linked to the rear differential 27 via left and right axle shafts 29 and 31.

  The torque of the engine 17 is transmitted from the transmission 19 to the transfer 21. On the other hand, the transfer 21 is transmitted to the ring gear 13 of the front differential 3 through the propeller shaft 23 and the bevel gear 15. Torque is transmitted from the front differential 3 to the left and right front wheels 9 and 11 via the left and right axle shafts 5 and 7.

  Torque is transmitted from the transfer 21 to the rear differential 27 via the propeller shaft 25 on the other side. Torque is transmitted from the rear differential 27 to the left and right rear wheels 33 and 35 via the left and right axle shafts 29 and 31.

  Therefore, the vehicle can travel in the four-wheel drive state by the left and right front wheels 9 and 11 and the left and right rear wheels 33 and 35. When the front differential 3 is locked by the operation of the solenoid actuator 1, the differential of the front differential 3 is locked, and the running performance on a rough road can be improved.

[Differential equipment]
The front differential 3 is, for example, as shown in FIG. FIG. 2 is a sectional view of the front differential 3 in an unlocked state and a locked state. The upper half of FIG. 2 shows the unlocked state, and the lower half shows the locked up state. 2 is opposite to that in FIG. 1, the right of FIG. 2 is the left of FIG. 1, and the left is the same.

  As shown in FIG. 2, left and right side gears 39 and 41 of the differential mechanism are rotatably provided in the front differential 3 in the differential case 37. A pinion gear 43 is engaged with the side gears 39 and 41. The pinion gear 43 is rotatably supported on the differential case 37 by a pinion shaft 45. The pinion shaft 45 is prevented from being removed by the pin 46 of the differential case 37. The left and right side gears 39 and 41 are connected to the axle shafts 5 and 7 of the left and right front wheels 9 and 11 in an interlocking manner.

[Solenoid actuator]
FIG. 3 is an enlarged cross-sectional view of a portion A in FIG.

  2 and 3, the solenoid actuator 1 includes a solenoid 47 and a plunger 49, and drives the lock-up member 51 in the axial direction.

  The solenoid 47 is connected to the controller side via a harness. The solenoid 47 generates an electromagnetic force according to current control, and includes a yoke 53 and a coil 55.

  The yoke 53 is a fixed iron core formed in a circular shape by a magnetic material, and is arranged concentrically with the rotational axis of the front differential 3. The yoke 53 is rotatable relative to the differential case 37, and is positioned and supported in the radial direction and the axial direction so as to be relatively rotatable on the differential case 37 side of the differential mechanism, and to the differential carrier 4 which is a fixed side. On the other hand, there is a detent.

  The outer circumference of the yoke 53 is fitted in a yoke fitting recess 57 of the differential case 37 so as to be relatively rotatable, and is positioned in the radial direction. A circumferential groove 59 is provided on the outer peripheral surface of the yoke 53, and the positioning plate 61 on the differential case 37 side is engaged to perform axial positioning. The positioning plate 61 is fixed to the end surface of the differential case 37 by bolts 63.

  A suction part 68 is formed on one side wall 65 of the differential case 37 corresponding to the yoke 53. The yoke 53 is disposed so as to be inhibited from relative movement in the axial direction and the radial direction with respect to the differential case 37. One side wall 65 of the differential case 37 is made of a magnetic material and forms a fixed iron core together with the yoke 53.

The plunger 49 is a movable iron core that is formed in a circular shape, is arranged on the inner circumference side of the fixed iron core, and is supported on the differential case 37 side so as to be movable in the axial direction. Plunger 49 is
It is coaxially arranged with respect to the suction part 68 of the one side wall 65 which is a fixed iron core, and can be sucked and moved in the axial direction by the suction part 68. The plunger 49 includes a magnetic action part 69 made of a magnetic material and a linkage action part 71 made of a non-magnetic material. The linkage action part 71 is integrally or integrally formed with the magnetic force action part 69 by welding or press fitting. The linking action portion 71 is fitted and supported on the outer periphery of the boss portion 72 of the differential case 37 and can be moved in the axial direction by suction. A tapered part 73 having a gentle slope is formed on the outer periphery of the end of the magnetic force acting part 69.

  The lock-up member 51 is formed in a ring shape and is disposed in the differential case 37 on one side of the differential device 3. The lock-up member 51 is formed with a linking projection 75 on one side and meshing clutch teeth 77 on the other side.

  The linking protrusions 75 protrude from the linking holes 79 formed at a plurality of locations in the circumferential direction on the one side wall 65 of the differential case 37 toward the plunger 49 and abut against the linking action portion 71. The meshing clutch teeth 77 are opposed to the meshing clutch teeth 83 of the differential device 3 so that they can mesh with each other. The meshing clutch teeth 83 are provided on the back surface of the side gear 41.

  A return spring 85 for the lock-up member 51 is provided between the side gear 41 and the lock-up member 51. A thrust washer 87 is interposed between the differential case 37 and the side gear 41.

  Reference numeral 81 denotes a space, which is formed so that the magnetic flux loop 80 formed in the yoke 53, the plunger 49, and the one side wall 65 does not cause an abnormal magnetic flux leakage when a current is applied to the solenoid 47.

[Suction part]
4 is an enlarged cross-sectional view of the suction portion, FIG. 5A is a partially cutaway perspective view of one side wall as the fixed iron core according to the first embodiment, and FIG. 5B is one side wall of the comparative example. It is a part notch perspective view.

  As shown in FIGS. 3 to 5, the suction portion 68 is provided on the one side wall 65 in a circular shape. The suction portion 68 is formed to protrude toward the yoke 53 side. A recess 89 is formed on the outer peripheral side of the suction portion 68 in the radial direction. The depression 89 reduces the thickness of the suction portion 68 in the radial direction as compared with the comparative example of FIG. The comparative example of FIG. 5B is a conventional one side wall 65A having no recess, and the recess 68A is not formed in the suction portion 68A, and the radially outer peripheral side has a large round shape 89A.

  In this embodiment, the depression 89 can suppress the magnetic force from flowing in the radial direction. The hollow portion 89 is formed of, for example, two orthogonal surfaces 91 and 93 in the radial direction and the axial direction.

  An inclined surface 95 continuous with the surface 93 is formed at the tip of the suction portion 68. The inner peripheral surface 97 of the suction part 68 has the same diameter in the axial direction. A tapered portion 73 of the magnetic force acting portion 69 can be fitted in the inner peripheral surface 97.

[Lock, Unlock]
When the current of the solenoid 47 is not controlled, the lock-up member 51 is urged by the urging force of the return spring 85, the meshing clutch teeth 77 and 83 are not meshed, and the differential device 3 is unentrained as shown in the upper half of FIG. It is locked.

  Accordingly, torque can be transmitted from the differential case 37 to the left and right side gears 39 and 41 via the pinion shaft 45 and the pinion gear 43, and the difference between the left and right side gears 39 and 41 can be achieved. Dynamic rotation is also allowed.

  Thus, the differential device 3 can perform torque transmission in a state where the differential between the front wheels 9 and 11 is allowed.

  When the solenoid 47 is current-controlled by energization, a magnetic flux is formed across the yoke 53, the one side wall 65, and the magnetic force acting portion 69 of the plunger 49, and the plunger 49 is attracted and moved in the axial direction.

  By the movement of the plunger 49, the linkage action part 71 presses and moves the lock-up member 51. Due to this pressing movement, the lock-up member 51 moves against the urging force of the return spring 85. By the movement of the lock-up member 51, the meshing clutch teeth 77 mesh with the meshing clutch teeth 83, and the side gear 41 is engaged and locked to the differential case 37 side via the lock-up member 51. By this engagement lock, the pinion gear 43 of the differential device 3 becomes unable to rotate, and the differential device 3 is locked up as in the lower half of FIG.

  In this way, the differential device 3 can perform torque transmission with the differential between the front wheels 9 and 11 locked.

[Effect of Example 1]
In the first embodiment of the present invention, one side wall 65 which is a fixed iron core around which a coil 55 is wound and which has a suction portion 68, and is arranged coaxially with respect to the suction portion 68 of the one side wall 65. In the solenoid actuator 1 provided with a plunger 49 which is a movable iron core that can be sucked and moved, a hollow portion 89 for reducing the radial thickness of the suction portion 68 on the radially outer peripheral side of the suction portion 68. Therefore, it is possible to suppress the magnetic force from flowing in the radial direction. Therefore, it is possible to suppress the suction force from dropping during the stroke of the suction movement of the plunger 49 and to improve the reliability by a reliable operation.

  6 and 7 are graphs showing the relationship between the displacement of the plunger 49 and the suction force. 6 and 7, a line segment 99 is a characteristic according to the first embodiment of the present invention, a line segment 101 is a characteristic using the comparative example of FIG. 5B, and a line segment 103 is a return spring shown together. It is an elastic characteristic of 85.

  When the plunger 49 is displaced and the return spring 85 is bent, the elastic force is increased as shown in FIGS. The suction force by the suction portions 68 and 68A is increased in accordance with the increase in the elastic force.

  Here, the difference between the case of the one side wall 65 of Example 1 in FIG. 5A and the case of the comparative example in FIG. 5B is that a suction force drop 105 appears in the latter.

  If the suction force drop 105 exists, the drop 105 may fall below the elasticity when the setting of the return spring 85 is changed and the elasticity is increased as shown in FIGS. For this reason, it is possible to quickly and surely perform the unlocking by returning the lock-up member 51 due to the increase in the elastic force, but the depression 105 causes a malfunction in the lock-up operation of the lock-up member 51. There is a fear and it will be unreliable.

  On the other hand, according to the structure of the first embodiment in which the suction force drop 105 does not exist, the lock-up operation of the lock-up member 51 is performed while changing the setting of the return spring 85 to increase the resilience as much as possible. Can be made sure.

  FIG. 8 is a graph showing the relationship between the magnetomotive force and the attractive force of the solenoid actuator. In FIG. 8, a line segment 107 indicates the characteristics according to the first embodiment, and a line segment 109 indicates the characteristics of the comparative example.

  As shown in FIG. 8, even in a region where the magnetomotive force is low, a large thrust can be secured in the plunger 49, and the reliability of the lock-up operation can be maintained from this point.

  9 and 10 relate to the second embodiment of the present invention, FIG. 9 is a cross-sectional view of the front differential, and FIG. 10 is an enlarged cross-sectional view of a portion B in FIG. The upper half of FIG. 9 is in an unlocked state, and the lower half is in a locked up state.

  The basic configuration is the same as that of the first embodiment, and the same or corresponding components will be described with the same reference numerals or B added to the same reference numerals.

  In the differential device 3B of this embodiment, the structure of the solenoid actuator 1B is slightly changed.

  In the first embodiment, the one side wall 65 is disposed so as to rotate relative to the yoke 53. However, in this embodiment, the one side wall 65B is formed separately from the differential case 37B as shown in FIGS. A fixed iron core is configured by being integrally coupled to the 47B yoke 53B by welding or the like. The suction part 68 of the one side wall 65 </ b> B includes a recessed part 89 as in the first embodiment.

  The yoke 53B is integrally coupled to the slide ring 111 by welding or the like. The slide ring 111 is formed of a non-magnetic material such as stainless steel, aluminum, copper or the like and has an L-shaped cross section, and is fitted to the boss portion 113 of the differential case 37B so as to be relatively rotatable. The slide ring 111 is positioned by a washer 115 assembled to the boss portion 113.

  An engagement plate 117 is attached to the linkage protrusion 75B of the lock-up member 51B outside the differential case 37B. On the inner peripheral side of the engagement plate 117, the linkage action portion 71B is opposed in the axial direction.

  Therefore, by controlling the current to the coil 55, the magnetic flux loop 80 is formed by the yoke 53B, the one side wall 65B, and the plunger 49B. By performing the suction movement, the same lock-up operation as in the first embodiment can be obtained.

Further, the recessed portion 89 of the suction portion 68 can improve reliability by a reliable operation as in the first embodiment.
[Others]
Solenoid actuators 1 and 1B can be applied to actuators of devices other than rear differentials, center differentials, and differential devices, or linear solenoids used in electromagnetic valves, in addition to front differentials 3 and 3B. it can.

(Example 1) which is a skeleton top view of a four-wheel drive vehicle. (Example 1) which is sectional drawing of a front differential. (Example 1) which is an expanded sectional view of the A section of FIG. (Example 1) which is an expanded sectional view of a suction part. (A) is a partially cutaway perspective view of one side wall (Example 1), and (b) is a partially cutaway perspective view of one side wall of a comparative example. It is the graph which showed the relationship between the displacement of a plunger, and a suction force (Example 1 and a comparative example). It is the graph which showed the relationship between the displacement of a plunger, and a suction force (Example 1 and a comparative example). It is a graph of the relationship between the magnetomotive force and attractive force of a solenoid actuator (Example 1 and a comparative example). (Example 2) which is sectional drawing of the unlock state of the front differential 3. FIG. The expanded sectional view of the B section of Drawing 9 (example 2).

Explanation of symbols

1,1B Solenoid actuator 3,3B Front differential (differential device)
47, 47B Solenoid 49, 49B Plunger (movable iron core)
51, 51B Lock member 53, 53B Yoke (fixed iron core)
55 Coil 65, 65B One side wall (fixed iron core)
68 Suction part 89 Dimple part 91,93 Two orthogonal surfaces

Claims (4)

In a solenoid actuator comprising a fixed iron core around which a coil is wound and having a suction part, and a movable iron core arranged coaxially with respect to the suction part of the fixed iron core and movable in the axial direction by the suction part,
On the radially outer peripheral side of the suction part, a hollow part for reducing the radial thickness of the suction part was formed.
Solenoid actuator characterized by this. The solenoid actuator according to claim 1,
The solenoid actuator according to claim 1, wherein the hollow portion is formed by two surfaces orthogonal to the radial direction and the axial direction. The solenoid actuator according to claim 1 or 2,
The movable iron core drives a lock-up member for locking and unlocking the differential of the differential mechanism. A differential device according to claim 3, wherein
The fixed iron core is positioned and supported in a radial direction and an axial direction so as to be relatively rotatable on the differential case side of the differential mechanism and is prevented from rotating with respect to the fixed side.
The differential iron device is characterized in that the movable iron core is arranged on the inner peripheral side of the fixed iron core and supported on the differential case side so as to be movable in the axial direction.

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